noun
vaginal intercourse; vaginal sex
Clinical or formal term for penile-vaginal intercourse. In everyday conversation, more common expressions like セックス or 性交 are used.
膣性交は妊娠の可能性がある行為です。
Vaginal intercourse is an act that can lead to pregnancy.
医師は膣性交についての質問に答えた。
The doctor answered questions about vaginal intercourse.
Common colloquial term for sex. 膣性交 is more clinical and precise.
Compound of 膣 (ちつ, 'vagina') and 性交 (せいこう, 'sexual intercourse').